双齿围沙蚕(Perinereis aibuhitensis Grube)典型自然栖息地的沉积环境特征

在山东沿海选取了双齿围沙蚕(Perinereis aibuhitensis Grube)的典型栖息地——河口潮间带,通过测定、分析不同潮区(高潮区、中潮区和低潮区)和同一潮区不同深度(5 cm、15 cm、25 cm和50 cm)沉积物中H2S、有机物、碳、氮、含水率以及粒度等指标,对其沉积环境特征进行了研究.结果显示,高潮区沉积物H2S浓度显著低于其他2个潮区(P＜0.05),25 cm深度处的沉积物H2S浓度显著高于其他深度(P＜0.05).3个不同潮区的间隙水中H2S浓度和含水率无显著性差异(P＞0.05),不同深度沉积物的间隙水中H2S浓度和含水率也无显著性差异(P＞0.05).低潮区有机物含量和氮含量显著低于中潮区和高潮区(P＜0.05),不同潮区之间的碳含量无显著性差异(P＞0.05),不同深度的沉积物中有机物含量、氮含量和碳含量随深度的增加而逐渐升高.粉砂在3个潮区以及各个潮区不同深度的沉积物中所占的比例均为最大,砂所占比例最小.低潮区沉积物的中值粒径显著高于其他2个潮区(P＜0.05),而不同深度沉积物的中值粒径无显著差异(P＞0.05).实验显示,本研究所选取的双齿围沙蚕典型自然栖息地沉积物中的H2S含量较高,并且随沉积物深度的增加而逐渐升高.沉积物中的有机物和碳含量极显著相关,碳氮含量显著相关.沉积物粒度分类属粘土质粉砂,高潮区沉积物的中值粒径显著小于低潮区,可能是造成高潮区沉积物的有机物含量和含水率显著高于低潮区的原因之一.

The Characteristics of the Sedimentary Environment in a Typical Habitat of Pernereis aibuhitensis Grube

Perinereis aibuhitensis Grube is an important feed for fish, shrimp, and crabs in the shores of China, and there have been extensive studies in biology, culturing technology and ecophysiology of this species. Although much less is known about their habitat environment, knowledge about this is important for us to better understand the biology of polychaete. In this experiment, we investigated various features of the sediments in different depths and tidal zones in a typical natural habitat of P. aibuhitensis, including hydrogen sulfide, organic matters, carbon, nitrogen, the moisture content, and the particle size. The results showed that the hydrogen sulfide concentration in the high tidal zone was significantly lower than those in the other two tidal zones (P<0.05). The hydrogen sulfide concentration was significantly higher in the depth of 25 cm than those in others (P<0.05). There was no difference in the hydrogen sulfide concentration and the moisture content of the pore water among three different tidal zones (P>0.05). There was also no difference in different depths (P>0.05). The contents of organic matters and nitrogen in the low tidal zone were significantly lower than those in the high and mid tidal zones (P<0.05). The levels of carbon were similar among different tidal zones (P>0.05). As the depth increased, the contents of organic matters and nitrogen in the sediment went up. The proportion of silt was the highest in all three tidal zones and in different depths of the same tidal zone, while the proportion of sand was the lowest. The median particle size in the low tide was higher than those in other two tidal zones (P<0.05). The median particle size remained unchanged in different depths (P>0.05). These results suggested that the hydrogen sulfide concentration was high in the sediment of the selected habitat of P. aibuhitensis. It became higher as the depth increased. There was a significant correlation between the contents of organic matters and carbon, and so were the contents of carbon and nitrogen. The dominant ingredient of the sediment was clayey silt. Compared to the low tidal zone, the high tidal zone had higher contents of organic matters and the moisture, which was probably caused by the smaller particles in this zone.